Grain aeration systems and techniques

ABSTRACT

In one embodiment, the invention is directed toward a networked grain aeration control system. For example, the system can provide centralized monitoring of the aeration of a number of grain storage facilities, thereby improving the management of stored grain. The networked grain aeration control system can allow the custodian of the system to offer an aeration service. Farmers, or other individuals, cooperatives, or companies can purchase the aeration service at a cost proportionate to the amount of stored grain to be aerated and the duration of storage. In this manner, the purchaser of the aeration service can avoid relatively high fixed costs that can be associated with various aeration hardware.

This patent application claims priority to U.S. Provisional ApplicationNo. 60/311,752, filed Aug. 10, 2001. The entire content of U.S.Provisional Application No. 60/311,752 is hereby incorporated byreference.

FIELD

The invention relates to the agricultural industry and, moreparticularly, to aeration systems for stored grain or other crops.

BACKGROUND

Agricultural crops, such as harvested grain, are often stored in grainstorage facilities, such as grain bins, which are usually clustered atvarious geographic sites. For example, individual farmers, cooperatives,or corporations often store grain after the grain is harvested in hopesthat the market price will increase. In addition, purchasers often storethe grain for periods of time, prior to milling, shelling, or otherprocessing of the grain.

Aeration systems and techniques have been developed to aerate storedgrain with the primary purpose of preventing spoilage from insect andmicrobial activity. In addition, aeration can be used to achieve orapproach a desired temperature and/or a desired moisture content forstored grain to increase its usability. Aeration can maintain, and insome cases, improve the quality of stored grain by achieving specifiedtargets for temperature and moisture content, allowing sellers toreceive higher prices for the grain, and allowing purchasers to maintainor improve the quality of grain that was purchased.

SUMMARY

In one embodiment, the invention is directed to a networked grainaeration control system. For example, the system can provide centralizedhigh-level control and logging capabilities for the aeration of a numberof grain storage facilities located at a number of different sites,thereby improving the management of stored grain. A networked grainaeration control system enables the custodian of the system to offer anaeration service to multiple grain storage customers. Using thenetworked grain aeration control system, the custodian can providecustomized configurations and strategies for a local controller from acentralized remote location, as well as log aeration operation and otherinformation such as weather data originating at different sites.

Farmers, or other agricultural producers, cooperatives, or companies canpurchase the aeration service at a cost proportionate to the amount ofstored grain to be aerated and the duration of storage. In this manner,the purchaser of the aeration service can avoid the fixed costsassociated with stand-alone controllers. In addition, the seller of theservice can regulate and meter the usage of the grain aerationtechnology.

In one embodiment, a networked grain aeration system includes a firstcontroller coupled to a first sensor and a first aeration fan positionedin proximity to a first agricultural crop storage facility located at afirst site, wherein the first controller controls the operation of thefirst aeration fan according to conditions sensed by the first sensor.The first sensor may be one of a first set of sensors coupled to thefirst controller located at the first site. In that case, the firstcontroller can control the operation of the first aeration fan, andpossibly additional fans positioned in proximity to additional cropstorage facilities at the first site according to conditions sensed bythe first set of sensors. The first controller provides tailored controlto the first fan so the grain in the first facility is managedindependently of other facilities at the site.

The system may also include a second controller coupled to a secondsensor and a second aeration fan positioned in proximity to a secondagricultural crop storage facility located at a second site, wherein thesecond controller controls the operation of the second aeration fan, andpossibly additional fans positioned in proximity to additional cropstorage facilities at a second site according to conditions sensed bythe second sensor. The second sensor may be one of a second set ofsensors coupled to the second controller located at the second site.Each facility at the second site can be managed independently of otherfacilities at the second site and other facilities at other sites. Thesystem may also include a central computer communicatively coupled tothe first and second controllers, wherein the central computer oversees,monitors and records operational data relating to the aeration at boththe first and second agricultural crop storage facilities. Inparticular, the central computer may log a history of sensed conditions,run time of the aeration fans, sensed conditions during the run times,and possibly other operational parameters used by the controllers.

The central computer may provide tailored configurations and strategieson a timely basis to the first and second controllers to improve theperformance of the local controllers. Although instructions to eachcontroller may be generated specifically with the grain in therespective facility in mind, the accumulated experience from allfacilities at all sites may be considered to refine control parametersand strategies delivered to each facility.

The first and second sensors may be temperature sensors, relativehumidity sensors, barometric sensors, or sensors having some combinationof temperature, barometric, and relative humidity sensing functionality,although the invention is not necessarily limited in those respects. Therespective controllers can use conditions sensed by each of the sensorsto identify appropriate run times for the aeration fans. In some cases,multiple (redundant) sensors are used by each respective aerationcontroller. In that case, diagnostic steps may be performed to assurethe sensed values are valid or to provide continued operation when onesensor may fail.

The agricultural crop storage facilities may be grain storage bins orother structures such as silos, bunkers, flat storages, or tanks. Thecentral computer can be communicatively coupled to the first and secondcontrollers located at the first and second sites respectively via anetwork, such as a packet based local area network, wide area network,or global network such as the Internet, or a public switching telephonenetwork (PSTN). The communication links may be wired or wireless. Insome instances, a site may be segregated into two or more subsets, eachwith a local controller that operates independently of each other. Eachlocal controller may be communicatively linked to the central computerto accommodate a number of circumstances. These circumstances mayinclude local network interferences, physical barriers such as railroadtracks, and electrical power distribution that may come from more thanone source.

The central computer may receive cumulative data from each localcontroller, and can parse, validate, store, and possibly organize dataincluding data sensed by the various sensors. For example, weatherinformation can be a valuable commodity that is gathered by the varioussensors, particularly when a large number of sensors are geographicallydistributed. This weather data may be sold and/or used, for example, toimprove weather prediction or even improve the ability to identify stormwarnings such as tornado warnings. In addition, information relating tothe operation time of the various fans can also be collected and storedby the central computer to help monitor system operation. The centralcomputer may create records that represent, for example, an aerationhistory for a particular lot of grain. These records could provideassurance as to the conditions the grain experienced during the entireperiod from harvest to consumption. For instance, these records couldreflect whether or not a condensing situation occurred that might fosterinsect or microbial activity occurred during the span of storage.Recorded operational parameters can be used to document the aeration ofa lot of grain, and may provide useful backup that can be downloaded toa replacement controller, e.g., in the event of controller malfunction,destruction, or failure.

One or more client computers may also be communicatively coupled to thecentral computer. For example, farmers or other purchasers of theaeration service may use client computers to access information relatingto their grain and the aeration service provided for that grain, e.g.,via a web browser interface. Each individual client computer may haveaccess only to the data that pertains to that particular client, i.e.,the purchaser of the service. In other words, a first client computermay not have access to data pertaining to a second agricultural cropstorage facility, and likewise, the second client computer may not haveaccess to data pertaining to the first agricultural crop storagefacility. Password protection and/or other security and authenticationmethods may be used to enable specific data delivery to the respectiveclient computers.

The system may utilize one or more algorithms to ensure that aeration isperformed at the desired times and under the appropriate circumstances.As one example, the present inventor has developed methods for aerationof stored grain as described in U.S. Pat. Nos. 4,688,332 and 4,522,335,which are hereby incorporated by reference in their entireties.Improvements on the methods of the aforementioned patents, however, canalso be implemented. For example, an aeration method may take intoaccount other variables, in addition to ambient conditions to achievebetter aeration results. Also, improvements to the techniques describedin the above-identified patents may also be used, such as truncation oftemperature bands or relative humidity bands for improved results incertain climates. In some cases, the truncation can be performeddynamically based on sensed data during recent accumulation of fanoperation or a climate history during past seasons. Such improvementsare described in greater detail below. The functions of theaforementioned patents and improvements to them can be executed at thelocal controllers to provide real-time capability. The central computercan download configuration files or other instructions from time to timein response to accumulated data from each local controller so personnelemployed for other duties at a grain storage site do not have to beskilled in grain aeration management.

Another variable that could be taken into account in a networkedaeration system, or even in a more conventional non-networked grainaeration unit, is heat produced by the aeration fan itself. For example,aeration fans can give off heat from the motor, and more notably,aeration fans may generate significant amounts of heat via frictionbetween the fan blades and the air. An aeration method or algorithmaccording to the invention may account for heat produced by operation ofthe aeration fan to yield better aeration results.

In one case, an aeration method makes an adjustment to sensed conditionsto account for fan size and the size of the grain storage facility. Forexample, given the fan size and the size of the grain storage facilityand its current contents, a theoretical offset of sensed ambienttemperature could be calculated. In other words, the offset canrepresent the difference between the ambient air temperature and thetemperature of the air after it has passed through the aeration fan.Accordingly, the offset can account for heat produced by the fan, andcan be used to more accurately select appropriate ambient air to forcethrough the grain so various targets may be achieved.

If used to modify the adaptive algorithm incorporated in theaforementioned patents, this offset would have the effect of shiftingthe starting point for a series of calculations to establish ranges ofacceptable ambient conditions for current aeration. This modification tothe targeted temperature (the ambient air average temperature or suchadjusted) could be accomplished by subtracting the calculated offsetfrom such targeted temperature. In turn, the sensed ambient relativehumidity would need to be adjusted using psychometric formulas to adjustfor the raised temperature. This method may be used in positive pressureaeration systems and not in negative pressure aeration systems.

Additionally, the method may account for static pressure within thefacility, e.g., at the location of an aeration fan or after the fan andprior to air entry into the grain. For example, the amount of staticpressure may be related to how full the facility is, relative to itscapacity. Because the amount of grain in a facility may change often, byaccounting for static pressure, a better approximation of the offset canbe achieved because the heat generated from the friction on the fanblade may be higher if static pressure is higher and may be lower ifstatic pressure is lower. If a static pressure sensor were employed, theoffset utilized in the above method could be calculated directly ratherthan theoretically.

In one particular case, which can be used in positive pressure aerationsystems, a feedback sensor, e.g., a feedback node (f-Node), is used tomeasure the actual temperature and/or relative humidity (RH) of airafter it has gone through the fan. The use of the f-node can achieve anactual measurement of the temperature offset and/or RH offset caused bythe operation of the aeration fan. The measured offset can then be usedas feedback to the aeration controller. The aeration controller can thencontrol the operation of the fans accordingly, accounting for bothambient conditions and the offset of air conditions relative to theambient conditions caused by fan operation. In general, ambient air withlower temperature and a higher relative humidity would need to beselected by the controller to achieve the desired targets since heatingair lowers relative humidity.

In accordance with the principles of the invention, a central computermay log the data received from the f-node to supplement the record fromother sensors to improve the reliability of modeling the conditionswithin the storage facility over a span of time. For example, this datacould be used to demonstrate that the grain stored inside the storagefacility was never exposed to conditions favorable for insect activityor the growth of microbes including fungus that can produce mycotoxins,allergens, or other conditions that may result in grain contamination.The documentation could increase the value of the grain and justify theadded cost of an f-node sensor because of increased confidence in thesafety of the grain, whether intended for human or animal consumption.

Another improvement to grain aeration management that can be provided bya networked system is electricity conservation and cost reduction. Witha networked system, contracts may be negotiated with suppliers of powerto grain storage operations to shed certain loads in high demand periodsin order to obtain lower rates. The total horsepower of aeration fansdeployed at a grain storage site on one or more facilities may rangefrom just a few to several hundred, to more than a thousand. The totalin the USA is estimated at 7,000,000 horsepower. Since a fan should notbe turned off with certain conditions existing in the grain, loadinterruption can only be accomplished with full knowledge of the stateof each grain facility or loss may result. However, conventionalaeration fans are often operated manually more than necessary to be onthe safe side because of a lack of information and skill regardingaeration practice.

A networked system could provide the necessary expertise to make thatdecision and to communicate with various power companies in real timeregarding their current load factor. If need be, the networked aerationsystem could accommodate requests for short duration shutdowns ofoperating fans to relieve power suppliers during peak demand periods. Anetworked system may have sufficient information and expertise to safelymanage fan operation around the competing goals of preventing spoilage,modifying moisture content, and economizing on electricity consumption,especially at certain times. In addition, a load queuing scheme may beemployed at each grain storage site so the total horsepower of the fansin operation at one time does not exceed specific levels for that site,or while certain other high load demands may be in use. Any suchimplementation may balance the respective considerations of thecondition of the grain, the targets set for the grain, the weather andseason and the cost of electricity and the extra charges of exceeding aspecified demand.

The invention can provide a number of advantages. For example, improvedaeration techniques can assure minimum or no deterioration, and mayactually improve the quality of stored grain. Indeed, aeration can helpensure that fungus producing mycotoxins, some of which can becarcinogenic, cannot live or flourish in the aerated grain. At aminimum, the aeration can ensure that mycotoxin levels, allergen levelsand other contaminate levels do not increase during storage, andtherefore, can help ensure that contaminant levels within the storedgrain are kept below acceptable levels.

Acceptable levels of contaminants, however, may correlate to smaller andsmaller amounts of contaminants per unit of grain as research on theeffects of contaminants continues to advance. In addition, aeration canbe effective in avoiding the loss of all of the grain in a facility tospoilage, the spoiling of a portion of grain with the resultingcontamination of unspoiled portions of grain within a facility due tomixing when removing the contents, preserving grain weight byeliminating the typical shrink due to moisture loss with manualoperation of aeration, minimizing insect infestation, achieving targetedmoisture content levels, achieving uniformity of kernel to kernelmoisture content, re-hydrating of over-dry grain, and drying of over-wetgrain within the limits of airflow availability. In addition, with grainstorage facilities with adequate aeration systems that are appropriatelymanaged, upstream practices of high heat drying may be eliminated ormodified. This reduction in harsh treatment of grain can reduce stresscracks and the subsequent breakage during handling as well asevaporation of certain volatiles from the grain. The entire networksystem can work toward generally preserving and possibly improving thequality of stored grain. For these reasons, precisely managed andcontrolled aeration may become an integral part of future grain storage.

Networked grain aeration also provides advantages in terms ofaccessibility of the data that is accumulated. For example, purchasersof the aeration service may be able to access data from remote computersconnected to the Internet. In other words, farmers can have access todata that shows them results of the service they are receiving. Inparticular, farmers, or others can have access to data that tracks theconditions surrounding the stored grain, and the various aerationmeasures taken on that grain. Such data can provide a history of storedgrain, allowing for trace ability and improved accountability of thestored grain. Even a chain of custody may be established and documented,in some cases, allowing the custodian of the grain to provide assurancesof safety.

In one implementation of the invention, a chain of custody isautomatically documented in the centralized computer of the networkedaeration system. The documentation can even be uploaded from the localcontroller or downloaded from the central server, for example, todelivery vehicles, when the stored grain is moved from a given storagefacility. For example, purchasers of the grain may desire informationdescribing the history of a particular lot of grain being purchased. Byallowing this information to be uploaded from computers at the storagefacility to accompany the grain during transportation or to be availableby other means at the point of delivery, verification for propersegregation at the next point of delivery may be enabled. In addition,if the grain merchandiser (such as a country elevator) also subscribesto the networked aeration service, he not only has assurance of thequality of a lot of grain before co-mingling with other lots of grain,but he can segregate lots of grain according to very high resolutionfactors not previously available. Additionally, the grain merchandisercould schedule deliveries originating from many different producers to acertain destination at a given time to assemble larger lots of grainwith highly consistent attributes that best meet his customer's needs.

Purchasers of grain and the end user (the public) can be more readilyassured of the safety of the purchased grain or products processed fromgrain or meat, milk, and eggs from livestock because of the detailedrecords and chain of custody enabled with a networked aeration system.

Centralized control and monitoring can also improve the level ofaeration quality, allowing the provider of the aeration service tocentrally monitor whether the individual aeration units are workingproperly. Another advantage of networked grain aeration includes theability to provide more effective control of aeration in variousgeographically distributed grain storage units. In other words, insteadof a local grain storage manager controlling aeration as he or she seesfit, centralized expertise can be used to monitor and more effectivelycontrol aeration. In addition, if device failure occurs, centralizedrecord keeping can allow information relating to recent climate andaeration fan operation to be downloaded to a new controller that may beinstalled following failure of a previous controller.

Networked grain aeration may also allow for a new and inventive pricingarrangement that can be attractive to prospective purchasers. In oneembodiment, the invention may comprise a method that includes monitoringaeration fans positioned in remotely located agricultural crop storagefacilities via a central computer of a networked grain aeration system,and charging fees related to an amount of grain and/or a span of time itis being stored in any given agricultural crop storage facility.

Farmers, cooperatives or other individuals or companies that areprospective purchasers of aeration control systems may be reluctant toinvest in aeration control hardware. For example, farmers may not wantto spend the fixed costs, given the unknowns associated with weather andcrop yield for any given year as well as marketing decisions. Theinvention can allow the seller of aeration control service to bear thefixed cost, and sell the aeration service at costs related to the amountof aeration service that is actually utilized. In this manner, thecharge for the aeration service may reflect the amount of grain beingaerated, and the time for which the grain is actually stored andaerated, which may vary. This method also overcomes a “free-rider”problem, wherein a purchaser of an aeration unit for a small storagefacility uses the aeration unit in a much larger facility or formultiple facilities. Such applications lower initial investments, butdeliver overall results that are deficient from those expected from arobust system.

In another method, the invention may include monitoring aeration fanspositioned in remotely located agricultural crop storage facilities viaa central computer of a networked grain aeration system and sellinggrain spoilage insurance for an amount of grain being stored in anygiven agricultural crop storage facility. Networked grain aeration canfacilitate the ability to guarantee against grain spoilage. Farmers maybe able to take out loans from a bank, based on the amount of harvestedcrops the fanner owns but has not yet sold. However, the banks maydesire, or even require the grain spoilage insurance to protect theirinvestments. The seller of aeration services, utilizing networked grainaeration having centralized control, may be able to provide thisinsurance because the centralized control allows the seller of theservice to adequately manage against grain spoilage and thereby protectthe grain assets and keep premiums affordable. Currently, grain storageoperations are burdened with the entire risk of spoilage, since noinsurance is available because of the difficulty of determiningappropriate and affordable premiums due to the haphazard methods ofcurrent grain storage practice and lack of record keeping.

Additional details of these and other embodiments are set forth in theaccompanying drawings and the description below. Other features, objectsand advantages will become apparent from the description and drawings,and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an exemplary networked grain aerationsystem.

FIG. 2 is a conceptual diagram of an agricultural storage facilitymaking use of a networked grain aeration system.

FIG. 3 is an exemplary block diagram of one embodiment of grain aerationsystem that can be installed in at a storage facility.

FIGS. 4-12 are flow diagrams illustrating techniques according tovarious embodiments of the invention.

DETAILED DESCRIPTION

The invention is directed to a networked grain aeration control system,various grain aeration techniques, pricing schemes for a grain aerationservice, and other techniques that can improve grain aeration and theaeration service. Using the system and/or techniques can improve theusefulness of stored grain. In this disclosure, the term grain refersbroadly to any harvested crop of seeds, including rough and smallgrains, maize, legumes, pulses or any other harvested agricultural cropthat is customarily stored in bulk and that can benefit from aeration.

FIG. 1 is a block diagram of an exemplary networked grain aerationsystem 10. For example, system 10 can provide centralized control,monitoring and/or historical logs of the aeration of grain in a numberof grain storage facilities 12. Any number of grain storage facilitiesmay be included in system 10. However, for simplicity, only twofacilities 12A and 12N are illustrated in FIG. 1. System 10 may improvethe ability to manage the aeration of stored grain. Moreover, networkedgrain aeration system 10 can allow the custodian of the system 10 tooffer an aeration service to multiple grain storage facilities viaunique pricing arrangements.

As shown in FIG. 1, networked grain aeration system 10 includes two ormore grain storage facilities 12. Each grain storage facility 12 can beequipped with an aeration fan 13 that is controlled by a respectiveaeration controller 14. For example, each aeration controller 14 maycomprise a computer controller that causes the respective aeration fan13 to turn on at times when effective aeration can occur. For example,aeration controller may control aeration fan 13 by invoking a controlnode as described below with reference to FIG. 3. In any case, one ormore sensors 16 may be coupled to each respective aeration controller 14to provide measurements of ambient conditions and measurementsassociated with the stored grain. The measured conditions may be used byaeration controller 14 to determine when to turn on the respectiveaeration fan 13.

Sensors 16, for example, may include temperature sensors and relativehumidity sensors. Separate temperature and relative humidity sensors maybe used at each storage facility 12, or a sensor having both temperatureand relative humidity sensing capabilities can be used. In addition,various other sensors such as temperature sensors positioned to measurethe temperature of the stored grain, sensors to measure barometricpressure, sensors to measure static pressure within the storagefacility, or feedback sensors that account for heat produced by theoperation of aeration fans 13 may also be used. Additional details ofthese and other sensors are provided in greater detail below. In anycase, aeration controller 14 controls aeration fans 13 based on sensedconditions and various input parameters to achieve a desired temperatureand moisture content of the stored grain, with or without a deadline.

For example, aeration controller 14 may execute one or more aerationtechniques such as those described in U.S. Pat. Nos. 4,688,332 and4,522,335. U.S. Pat. Nos. 4,688,332 and 4,522,335 are incorporated byreference in their entireties. In particular, aeration controller 14 mayreceive input specifying a desired moisture content for the storedgrain. The controller may calculate a desired temperature best for thatgeographic location, or such desired temperature may be modified byinput in specific cases. Aeration controller 14 may define a temperatureband and a relative humidity band respectively around the desiredtemperature and a relative humidity that corresponds to the desiredmoisture content for a given temperature. For example, if the desiredtemperature is 48 degrees Fahrenheit, aeration controller 14 may definea temperature band of +/−2 degrees, i.e., 46 degrees to 50 degrees.Similarly, aeration controller 14 may define a relative humidity band of+/−2 percent.

The temperature band may depend on beginning grain temperature, or maysimply be a band defined about a target temperature determined inanother method for the grain. In one example, the target temperature isdetermined by an average temperature over a span of time, e.g., in oneuseful case, a twenty-one day moving average of ambient temperature.Aerating grain at or near its current temperature can help avoidmoisture migration in the stored grain. In other cases, the targettemperature can be offset to account for heat produced by aeration fan13, barometric pressure, extreme climate fluctuations, or othervariables. In addition, the target temperature may be dependent on thespecific type of grain to be aerated. Moreover, different targettemperatures may be selected based on whether re-wetting or drying isdesirable. The target temperature may also be offset from the averageduring extremely hot or extremely cold conditions or even in seasonalcases. The target temperature may also be adjusted to prepare the grainfor readiness for shipping if the destination is known or the grain willbe transported through a different climate. As an example, transportingcold grain through a tropical region by ship can result in severecondensation that encourages spoilage. Accordingly, in that case, thegrain may be warmed prior to transport.

The target relative humidity for a desired moisture content may betemperature dependent and may also depend on the current temperature ofthe grain. In addition, measurements of barometric pressure may be usedto adjust the target relative humidity for a given temperature. Also,the target relative humidity may be dependent on the specific type ofgrain to be aerated. Moreover, a different target relative humidity fora given moisture content may be selected based on whether re-wetting ordrying is to occur. The size of the bands may vary in differentimplementations.

If sensor 16 identifies an ambient temperature within the temperatureband, say 47 degrees Fahrenheit, aeration controller 14 identifies thetarget relative humidity associated with the sensed 47 degreetemperature, e.g., 63 percent. In other words, the target relativehumidity may depend on the current ambient temperature, and furthermore,may also depend on the current temperature of the grain. In any case, at47 degrees, for example, if the ambient relative humidity is within therelative humidity band of say 61 percent to 65 percent (+/−2 percent of63 percent), then aeration controller 14 may activate aeration fan 13.Larger or smaller bands could also be defined. In addition, barometricpressure readings or other climate conditions could be used. In thatcase, aeration may occur only when the conditions surrounding storagefacility 12 fall within the defined climate conditions. Also, climateconditions, such as barometric pressure, for example, may be used toadjust the temperature and/or relative humidity targets and bands.

Aeration controller 14 may also have a regulator-like mechanism thatensures that the aeration fan 13 can only run for an allotted amount oftime, on average, in order to conserve power. For example, aerationcontroller 14 may budget an amount of time for a given time interval,e.g., four hours per day. In that case, aeration controller 14 wouldactivate aeration fan 13 for only four hours per day on average, even ifthe desired conditions of temperature and relative humidity were presentfor more than four hours per day.

Aeration controller 14 may also accumulate a backlog of time to accountfor unused time that was budgeted for aeration. Thus, if the desiredconditions were not present for two days, then twelve hours ofaccumulated budget may be used on the third day. In other words, thefour hour budgets for three days may accumulate to twelve hours, whichcan be used in succession once the desired conditions occur. Once theaccumulation of budgeted time is used, however, aeration fan 13 may beturned off even if the desired conditions are still present.

In addition, aeration controller 14 may define a backlog threshold, saytwenty hours (the equivalent of five days at four hours of budget perday). If the backlog exceeds the threshold, aeration controller 14 mayenlarge the temperature and/or relative humidity bands to improve thelikelihood that aeration will occur. This can help ensure that at leastsome aeration occurs even if the ambient conditions are sub-optimal. Thetemperature and/or relative humidity bands may return to the originallydefined values once the backlog does not exceed the threshold, oralternatively, the changed temperature and/or relative humidity bandsmay be used for longer periods of time once the change is invoked.

One extremely useful improvement to these aeration techniques mayinvolve the truncation of the temperature and/or relative humidity bandsto improve aeration for climate specific scenarios. In particular,aeration controller 14 may truncate the temperature and/or relativehumidity bands for different climate scenarios in a manner that causesaeration to achieve improved results in terms of more accuratelyachieving a target temperature and/or moisture content for the storedgrain.

For example, assuming a target temperature of 48 degrees and a targetrelative humidity of 63 percent, in drier climates if a symmetricrelative humidity band is defined around the target humidity, e.g., +/−2percent of 63 percent relative humidity, it will be likely that onaverage the aeration fan 13 will be activated during times of relativehumidity in the lower half of the humidity band, e.g., at relativehumidity between 61 and 63 percent. In that case, the actual temperatureand/or moisture content of the grain will be skewed away from the targeton the dry side, which is undesirable.

For this reason, aeration controller 14 may truncate the humidity bandfor dryer. climates, such that for example, if the target relativehumidity is 63 percent, then the relative humidity band can be definedto be −1, +3 of that value, i.e., 62 to 66 percent. In other words, thehumidity band can be made non-symmetric about the target humidity. Inparticular, for dry climates, the relative humidity band around thetarget relative humidity can be truncated to increase the wet side ofthe band relative to the dry side of the band. Such techniques cangreatly improve aeration in extreme climates. Drier climates may be morelikely to have a temperature of 48 degrees and a relative humidity belowthe target of 63 percent. Truncating the humidity band to account forsuch climate-specific phenomena can improve the quality of aeration,thereby creating a greater likelihood of achieving the actual targetmoisture content for the grain. Moreover, truncation can be particularlyhelpful to compensate for micro-climate phenomena, such as local climateeffects of lakes, rivers, forests, or the like.

Truncation may occur automatically at aeration controller 14, based onmeasured climate conditions during previous aeration. In other words,band truncation can be an adaptive feature implemented by aerationcontroller 14. For example, aeration controller 14 may truncate thehumidity band to the wet side, based on measured dry conditions duringearlier operation of aeration fan 13, or may truncate the humidity bandto the dry side, based on measured wet conditions during earlieroperation of aeration fan 13. Alternatively, truncation may occur viaprogrammed variables submitted by an aeration expert at central computer20, which is described in greater detail below. In any case, the extentof extreme climate conditions required to initiate an adaptivetruncation of the humidity band is subject to a wide variety ofimplementation-specific values.

The truncation feature may also be incorporated to improve aeration inwetter climates. In that case, aeration controller 14 may truncate thehumidity band for wetter climates, such that for example, if the targetrelative humidity is 63 percent, then the relative humidity band can bedefined to be −3, +1 of that value, i.e., 60 to 64 percent. In otherwords, for wet climates, the relative humidity band around the targetrelative humidity can be truncated to increase the dry side of the bandrelative to the wet side of the band.

Aeration controller 14 may be programmed to initially truncate thetemperature or relative humidity bands, or may be programmed to onlytruncate the bands in response to a band adjustment event, such as whenthe backlog exceeds the backlog threshold. Moreover, aeration controller14 may receive feedback of the conditions during which aeration fan 13has operated, and may adjust and truncate the band(s) based on theprevious conditions in order to more adequately achieve the targettemperature and moisture content for the stored grain. In any case,improved aeration can be achieved in a climate specific manner. Thelevel of truncation may vary in different implementations. Adaptivetruncation may provide responsive adaptation of the aeration, which canimprove aeration in extreme climates, and can adjust for microclimatefluctuations as they occur.

In accordance with the principles of the invention, system 10 alsoincludes a central computer 20 that may define or control the operationspecific parameters of the respective aeration controllers 14. Centralcomputer 20 can also log the information collected by sensors 16 as wellas the amount of time aeration fans 13 operate, the respective backlogs,the climate conditions during aeration fan operation times, and even thegrain temperatures associated with the stored grain in the respectivestorage facilities 10.

Central computer 20 and aeration controllers 14 may operate in amaster-slave relationship, in which aeration controllers 14 provideinformation to central computer 20 in response to requests from centralcomputer 20. Requests for accumulated aeration data may occurperiodically, e.g., daily, hourly, or the like. Optionally, system 10may also support an alarm condition override in which a given controller14 is able to communicate to central computer 20 without being queried.Such an alarm condition to override the master-slave communicationprotocol can be effective in alerting central computer 20 of problems ordevice malfunctions associated with a given storage facility 12.

Central computer 20 can provide improved control and custodial care ofthe aeration of stored grain. Farmers, or other agricultural producers,cooperatives, or companies may purchase the aeration service at a costproportionate to the amount of stored grain to be aerated and theduration of storage. In this manner, the purchaser of the aerationservice can avoid relatively high fixed costs that can be associatedwith various aeration hardware such as aeration controller 14. Inaddition, the seller of the service can control and meter the usage ofthe grain aeration technology.

Central computer 20 may provide the input parameters to the differentaeration controllers 14. The input parameters may include the type ofgrain, the target temperature, the target moisture content, the size ofthe temperature and relative humidity bands, the amount and timing oftruncation, if desired, the size of the aeration budget, the backlogthreshold, and any changes that should occur in response to overcomingthe backlog threshold. In some cases, one or more of these inputvariables may be defined by an operation mode selected for a respectiveaeration controller 14. In any case, the input variables can be defineddifferently for various different aeration controllers so as to accountfor different types of grains, different climates or microclimates, orother variables that may distinguish the operation of aeration fans atdifferent facilities. In some cases, input can be provided in the formof objectives, e.g., desired moisture content and a target deliverydate.

The use of central computer 20 to accomplish the programming of inputvariables and/or mode selection, that would otherwise require onsiteattention, can improve aeration significantly and reduce costsassociated therewith. In particular, travel to on-site locations can beavoided, training of service persons can be reduced, and a moreknowledgeable person operating the central computer 20 can set parametersettings. In some embodiments, the operation of central computerrelative to controllers 14 can be automated as well, eliminating humanerror.

Also, central computer 20 can improve aeration by providing betterquality control of the aeration. For example, central computer 20 mayfacilitate the ability to recognize sensor malfunctions by comparingsensed ambient conditions of one facility 12 to those of anotherfacility in close geographic proximity, e.g., at the same site. Uponidentifying possible malfunctions, replacement parts or service may beprovided more quickly, which can further improve aeration services.

Central computer 20 may also log the various parameters, settings andmeasurements accumulated by the respective aeration controller 14.Historical logs may provide a number of advantages. For example, ambientcondition sensor data may provide extensive history of weather trends.Accordingly, such information may be useful to weather centers or otheragencies concerned with weather prediction and trends. Also, thehistorical logs may provide useful backup, if for example, a givenaeration controller 14 malfunctions or is destroyed. In that case, aftera replacement aeration controller is installed, the history of aeration,backlog and other variables needed to continue the aeration in the samemanner as prior to the failure can be downloaded to the new aerationcontroller. Accordingly, historical logs on central computer can improvethe robustness of system 10 in the event of a device failure.

Logs stored on central computer 20 may also enable the ability to trackand verify the history of a lot of grain. In other words, logs oncentral computer 20 may be maintained for both aeration controllerspecific tracking purposes, and also grain specific tracking purposes.If a log of grain is moved from one facility to the next, the grainspecific log may track the lot of grain to provide a history of itstemperature and moisture content. In that case, a download ofinformation from the central computer 20 which it received from thefirst aeration controller that originally controlled the grain can bemade to the second aeration controller that subsequently controls thegrain. Moreover, networked grain aeration system 10 can facilitate thisdata transfer without requiring on-site attention.

In one implementation of the invention, a chain of custody isautomatically documented over time by the networked aeration system andstored in central computer 20. The documentation can even be downloaded,for example, to delivery vehicles, when the stored grain is moved from agiven storage facility. The information may be uploaded from the givenaeration controller 14 to the delivery vehicle, or downloaded from thecentral computer 20 to the delivery vehicle. In either case, the centralcomputer 20 can log the current location and track the grain to improveaccountability and trace ability.

Purchasers of the grain may desire information describing the history ofa particular lot of grain being purchased. By allowing this informationto be downloaded from central computer 20, purchasers can be morereadily assured of the aeration history and chain of custody of thegrain. This data, in turn, can provide a better assurance of safety andquality of the purchased grain. In some cases, grain given the stamp ofapproval of the aeration service provider may demand a premium price.

Historical tracking and verification of grain can further provide theability to demand premium prices, for example, for grain that wassystematically maintained in only high-quality settings in terms oftemperature and relative humidity for the life of the grain.Furthermore, centralized control and robust aeration management may alsoprovide the ability to insure against grain spoilage. For example, withcentralized control and robust monitoring capabilities, the custodian orsome other entity may be able to offer grain spoilage insurance tofarmers that own the allotments of grain, e.g., on the condition thatthe grain aeration control services are used. With the ability todefine, monitor and update aeration via centralized computer, thecustodian can better ensure that spoilage will not occur, and thereforecan be better positioned to provide grain spoilage insurance at anaffordable price.

One or more client computers 21A and 21B may also be communicativelycoupled to the central computer 20, such as via network 18. Using clientcomputers 21A and 21B, farmers or other purchasers of the aerationservice may access information relating to their grain and the aerationservice provided for that grain. Each individual client computer 21 mayhave access only to the data that pertains to that particular client,i.e., the purchaser of the service. In other words, a first clientcomputer 21A may not have access to data pertaining to a secondagricultural crop storage facility 12N, and likewise the second clientcomputer 21N may not have access to data pertaining to the firstagricultural crop storage facility 12A. A password access function maybe used to gain access to the data, e.g., via a web browser interface.In addition, more sophisticated security and authentication protocolscan be employed.

In some embodiments, customers may be able to select aeration objectivesfor their grain. For example, using client computer 21, the customer maybe able to select a desired moisture content and a desired deliverydate. Central computer may receive the user input selecting aerationobjectives, and may program the appropriate aeration controller 14 so asto achieve the objectives. If a delivery date is selected, the aerationcan be made to occur over time in a manner that achieves the desiredmoisture content at that delivery date. Also, if a delivery location isdefined, the aeration may be defined to purposely dry (wet) the grain ina manner commensurate with an amount of wetting (drying) that wouldpredictably occur during grain delivery. For example, if the grain is tobe shipped across the ocean, aeration can be adjusted to purposely drythe grain, knowing that wetting will occur during shipment.

Network 18 may comprise a packet based network such as the Internet, ora smaller public or private packet based network. Alternatively, network18 may comprise a public switch telephone network (PSTN), or any othernetwork sufficient to transfer information between the aerationcontrollers 14 and central computer 20 and the various client computers21 and central computer 20. Various levels of security, such as firewalls or virtual private networks (VPNs), may also be implemented toensure that information transferred through network 18 is secure.

As mentioned above, various other modifications could also be made toaeration controllers 14 to improve aeration. For example, in accordancewith the principles of the invention, one particular variable that couldbe taken into account by a respective aeration controller 14 is heatproduced by the respective aeration fan 13. For example, aeration fans13 can give off heat from the motor, or more notably, aeration fans 13may generate significant amounts of heat via friction between the fanblades and the air. In either case, the heat produced by operation ofaeration fans 13 may blur the relationship between the ambienttemperature measurements by sensors 16 and the actual temperature of airthat will be forced into the facility upon activation of an aeration fan13. Accordingly, an aeration method or algorithm executed by aerationcontroller 14 may account for heat produced by the aeration fan to yieldbetter aeration results.

In one case, an aeration method executed in aeration controller 14 makesa theoretical adjustment to sensed conditions by accounting for fan sizeand the size of the grain storage facility. For example, given the fansize and the size of the grain storage facility, a theoretical offset tosensed conditions can be calculated. This offset may be programmed intoaeration controller 14, such as via a communication from centralcomputer 20 to the aeration controller 14. In any case, the offset canaccount for heat produced by the fan, and can be used to more accuratelydefine the actual air temperature or humidity that will be introduced tothe storage facility upon operation of the aeration fan 13. In thismanner, improved control of the conditions within the grain storagefacility can be achieved. The offset may be determined experimentally ormathematically. In either case, the offset may be used to adjustmeasured ambient temperature to provide a better estimate of the actualtemperature of air introduced by aeration fan 13. Moreover, the offsetmay be used to adjust the target temperature defined by aerationcontroller 14, e.g., to adjust the twenty-one day moving average ofambient temperature to compensate for the offset caused by heatproduction of aeration fan 13. Adjusting the target temperature based onheat produced by aeration fan 13 will likewise cause temperature bandadjustment in a manner that accounts for heat production of aeration fan13.

Additionally, a method executed in aeration controller 14 may alsoaccount for static pressure within the facility (specifically, forexample, at the location of an aeration fan or the entry point of airinto the grain). For example, the amount of static pressure may berelated to how full the facility is, relative to its capacity. Byaccounting for static pressure, a better approximation of the offset canbe achieved because the heat generated from the friction on the fanblade may be higher if static pressure is higher and may be lower ifstatic pressure is lower.

In one particular case, a feedback sensor, e.g., a feedback node(f-node) described in greater detail below, is used to measure theactual temperature and possibly relative humidity (RH) of air after ithas gone through the fan. The f-node may also sense static pressure, ifdesired. The use of the f-node can achieve an actual measurement of theoffset, which can then be used as feedback to the aeration controller14. The aeration controller 14 can then adjust the operation of theaeration fan 13 accordingly.

Also, modified air-conditions measured by the feedback sensor can beused to define a more useful target temperature and target relativehumidity for the bands. In other words, the target temperature andtarget relative humidity may be adjusted based on feedback measurementsof actual conditions within a facility. One or more feedback nodes maybe positioned after the aeration fan 13 but prior to the stored grain,e.g., in the plenum. Also, feedback nodes may be positioned in theexhaust of a crop storage facility 12, or in different strata of thegrain to provide a number of storage measurements.

System 10 may also be configured to log and record the data of thef-node to provide data demonstrating the actual conditions within thestorage facility over time. In other words, the data from an f-node maybe logged by central computer 20 for later examination or use. Forexample, such f-node data could be used as documentation to demonstratethat the grain inside the storage facility was never exposed toconditions favorable or susceptible to the growth of microbes includingfungus that can produce mycotoxins, allergens, or other contaminants.This documentation, in turn, could increase the value of the grain andjustify the added cost of an f-node sensor. Recording actual conditionsinside the storage facility during aeration may also occur in the eventof manual override during which an aeration fan is turned on manuallyon-site. Information defining conditions during manual override may beused later to adjust aeration in order to improve aeration results interms of achieving a target temperature and moisture content. In thismanner, centralized monitoring can improve accountability of theaeration because manual overrides are documented and subsequently usedto adjust the aeration, as needed, to achieve the desired temperatureand moisture content.

FIG. 2 is a conceptual diagram of an agricultural storage facilitymaking use of a networked grain aeration system. In this example, theagricultural storage facility comprises a grain bin 22 that stores grain23. Grain bin 22 is fitted with an aeration fan 13 that is controlled byaeration controller 14. Aeration controller 14 comprises a computercontroller that controls operation of aeration fan 13 according to anaeration algorithm such as those described in U.S. Pat. No. 4,688,332 or4,522,335. Additionally, aeration controller 14 may execute moreadvanced aeration techniques described herein, such as techniques thatutilize feedback sensor 29 to further improve the quality of aeration.Also, aeration controller 14 may execute aeration techniques thatutilize truncated temperature or relative humidity bands to improveaeration for climate specific scenarios as outlined herein. Furthermore,the truncation feature can be an adaptive feature of aeration controller14 such that temperature bands or relative humidity bands used to defineaeration fan operation times can be adjusted based on previousconditions during which the aeration fan has operated. Heaters, misters,or other grain conditioning devices (not shown) may also be controlledby aeration controller 14.

Aeration controller 14 may be coupled to a computer network 18. In thismanner, as outlined above, the sensed information collected by aerationcontroller 14 and operation of aeration fan 13 can be centrally loggedand monitored by a central computer (not shown in FIG. 2). Clientcomputers connected to network 18 may also gain client-specific accessto such information.

In operation, temperature sensor 26 measures ambient temperature andprovides the measurement of ambient temperature to aeration controller14. Similarly, relative humidity sensor 27 measures ambient relativehumidity and provides the measurement of relative humidity to aerationcontroller 14. Sensors 26 and 27 may comprise separate components or anintegrated sensor that provides sensing functionality for bothtemperature and relative humidity. Temperature sensor 28 measures thetemperature of stored grain 23 and provides the measurement to aerationcontroller 14. In addition, a barometric pressure sensor may be used byaeration controller 14 to adjust a target relative humidity for a givenair temperature. Barometric pressure measurements used to adjust atarget relative humidity for a given air temperature can be particularlyuseful to compensate for elevation of the storage site, relative to sealevel.

Aeration controller 14 can be programmed with input specifying a desiredtemperature and moisture content for the stored grain. Aerationcontroller 14 may define a temperature band and a relative humidity bandrespectively around a target temperature and a target relative humiditythat corresponds to the desired moisture content for a giventemperature. The target temperature may be selected based on a desiredtemperature, or based on a desired temperature relative to the currenttemperature of grain 23. In one example, the target temperature isdefined by a twenty-one day moving average of ambient temperature. Inany case, a temperature band can be defined about the targettemperature, and a relative humidity band can be defined about a targetrelative humidity, which may be temperature dependent. The size of thebands may vary widely in different implementations.

If sensor 26 identifies an ambient temperature within the definedtemperature band, say 47 degrees, aeration controller 14 identifies thetarget relative humidity associated with the 47 degree temperature, say63 percent. The target relative humidity may be dependent on the currentambient temperature, and may also be dependent on the currenttemperature of grain 23, e.g., dependent on the ambient temperaturerelative to the temperature of grain 23. Aeration controller 14 mayaccess a lookup table in memory (not shown) or it may calculate frompsychometric formulas to identify the target relative humidity given anambient temperature and possibly a current grain temperature. In anycase, if relative humidity sensor 27 measures a relative humidity withinthe relative humidity band of the target relative humidity, say 61percent to 65 percent (+/−2 percent of 63 percent), then aerationcontroller 14 may activate aeration fan 13. A control node (not shown inFIG. 2) may be used to execute fan activation in response to controlsignals sent from aeration controller 14.

A feedback sensor 29 may also be used to measure a temperature offsetcaused by heat production associated with aeration fan 13. Heat fromaeration fan 13 may offset the temperature of air introduced to grainbin 22 (as illustrated by the arrows) away from the ambient temperaturemeasured by temperature sensor 26. Accordingly, feedback sensor 29 canbe used to provide a more accurate temperature measurement once fan 13is turned on. The offset measured by feedback sensor 29 can be used toadjust the aeration accordingly. Additionally or alternatively, themeasurements of feedback senor 29 may be used to provide actualmeasurements of temperature and/or relative humidity introduced to grainbin 22. Such information may be logged by central computer 20 (FIG. 1)to provide a more accurate history of the aeration of grain 23.

Alternatively, rather than implement a feedback sensor 29, the heatproduced by fan 13 may be accounted for by a theoretical orexperimentally determined offset value, which may be used to adjust themeasured ambient temperature during execution of the aeration algorithm.In this manner, heat produced by fan 13 may not undermine theeffectiveness of aeration. Instead, the temperature band used byaeration controller 14 (as outlined above) may be defined around anambient temperature measured by temperature sensor 26 plus thetheoretical offset. A measurement of static pressure may be used in thegeneration of the theoretical offset. Additionally, the temperatureband, or the relative humidity band may be truncated as described hereinto improve aeration for climate specific scenarios.

If desired, additional feedback sensors may also be positioned atvarious locations of grain bin 22. For example, one or more feedbacksensors may be positioned after the aeration fan 13 but prior to thestored grain, e.g., in the plenum. Also, feedback sensors may bepositioned in the exhaust of a crop storage facility 12, or in differentstrata of grain 23 to provide a number of storage measurements.

Aeration controller 14 may also implement a regulator-like mechanismthat ensures that the aeration fain 13 can only run for an allottedamount of time, on average, which can conserve power and avoidunnecessary aeration. For example, aeration controller 14 may budget anamount of time for a given time interval, say four hours per day.Aeration controller 14 may also accumulate a backlog of time to accountfor unused time that was budgeted for aeration. Thus, if the desiredconditions were not present for two days, then twelve hours ofaccumulated budget may be used on the third day. In other words, thefour hour budgets for three days may accumulate to twelve hours, whichcan be used in succession once the desired conditions occur. Once theaccumulation of budgeted time is used, aeration fan 13 may be turned offeven if the desired ambient conditions are still present.

In addition, aeration controller 14 may define a backlog threshold, saytwenty hours (the equivalent of five days at four hours of budget perday). If the backlog exceeds the threshold, aeration controller mayenlarge the temperature and/or relative humidity bands to improve thelikelihood that aeration will occur. This can help ensure that at leastsome aeration occurs even if the ambient conditions are sub-optimal.

Also, as described above, aeration controller 14 may implement aerationtechniques in which truncation of the temperature and/or relativehumidity bands are performed to improve aeration for climate specificscenarios. In particular, aeration controller 14 may truncate thetemperature and/or relative humidity bands for different climatescenarios in a manner that causes aeration to achieve improved resultsin terms of achieving a target temperature and/or moisture content. Thetruncated band(s) may be predefined for a known climate, or may beadaptively altered by aeration controller 14 based on the actual climatemeasured during the times when aeration fan 13 operates. In one example,adaptive truncation of a relative humidity band based on actual climatemeasured during the times when aeration fan 13 has operated may be anadvanced operation mode of aeration controller 14, that can be selectedor enabled by central computer 20.

Aeration controller 14 may truncate the humidity band for dryerclimates, such that for example, if the target relative humidity is 63percent, then the relative humidity band can be defined to be −1, +3 ofthat value, i.e., 62 to 66 percent. In other words, the humidity bandcan be made non-symmetric about the target humidity. Such techniques cangreatly improve aeration in extreme climates. Similarly, the truncationfeature may also be incorporated to improve aeration in wetter climates.In that case, aeration controller 14 may truncate the humidity band forwetter climates, such that for example, if the target relative humidityis 63 percent, then the relative humidity band can be defined to be −3,+1 of that value, i.e., 60 to 64 percent. Again, the level of truncationmay vary in different implementations.

Moreover, as mentioned, the truncation can be an adaptive feature thatchanges based on measured conditions during operation of aeration fan13. For example, the relative humidity band may originally be symmetricabout a target. In particular, given a target of 63 percent, therelative humidity band can be defined to be −2, +2 of that value, i.e.,61 to 65 percent. Thereafter, if operation of the aeration fan 13primarily occurs at periods of time during which measured relativehumidity is in the dry side of the band, i.e., between 61 and 63percent, then aeration controller may adaptively truncate the humidityband to enlarge the wet side of the band and decrease the dry side ofthe band.

In other words, if aeration controller 14 can determine that operationof the aeration fan 13 has primarily occurred at periods of time duringwhich measured relative humidity is in the dry side of the band. In thatcase, aeration controller 14 can modify the band to favor operationduring wetter periods of time, e.g., the band can be adaptively changedto be −1, +3 of the 63 percent target, i.e., 62 to 66 percent. Aerationcontroller 14 may continue to modify and adaptively alter the bands asaeration occurs in different weather. In some cases, the relativehumidity band may be originally defined symmetrically about the targetrelative humidity, then truncated to the wet side after fan operation indry conditions, then re-established in a symmetric band after thetruncation compensates for the previous dry conditions, and thenpossibly truncated to the wet side, e.g., if subsequent fan operationoccurs during extended wet conditions.

In this manner, adaptive truncation of the relative humidity band canachieve improved results in terms of achieving a target moisture contentfor the stored grain. In other words, adaptive truncation of climatebands can cause grain can be aerated in a manner that improves theability to achieve desired grain conditions. Threshold values forclimate parameters defined during operation of the aeration fan 13 canbe used to define when such adaptive truncation should occur, and aresubject to a wide variety of implementations.

Moreover, centralized control and monitoring of grain aeration can alsoimprove the level of aeration quality, allowing the provider of theaeration service to centrally monitor whether the individual aerationcontrollers 14 are working properly. Another advantage of networkedgrain aeration includes the ability to provide more effective aerationcontrol among various grain storage units. In other words, instead of alocal grain storage manager controlling aeration as he or she sees fit,central expertise can be used to monitor and more effectively controlaeration.

Networked grain aeration may also allow for a new and inventive pricingarrangement that can be attractive to prospective purchasers. Inparticular, fees may be charged in amounts commensurate to an amount ofgrain being stored in any given agricultural crop storage facility. Theduration of storage can also be reflected in the price. Such a pricingscheme can reduce fixed costs to individual farmers and improve thelikelihood of industry acceptance of such services. Such a pricingscheme may also overcome a “free-rider” problem, wherein a purchaser ofan aeration unit for a small storage facility uses the aeration unit ina much larger facility or for multiple facilities.

The results achieved by a free-rider may not be particularly greataeration results, but they may be nevertheless better aeration resultsthan would be achieved with no aeration control. Still, because thefree-rider often makes use of improperly sized aeration fans inoversized storage facilities, free-riders may undermine consumerconfidence in an aeration control product or service. In other words,prospective customers may view the results achieved by free-riders asinadequate and correlate inadequacy with the seller of the product. Infact, however, the free-riders may not be achieving the most effectiveresults. Thus, avoiding the free-rider problem may improve good willassociated with the seller of the aeration product or service, inaddition to forcing the free-rider to bear a more proportionate cost.

Centralized monitoring of aeration may also allow the selling of grainspoilage insurance for an amount of grain being stored in any givenagricultural crop storage facility. In other words, networked grainaeration can facilitate the ability to guarantee against grain spoilage.Farmers may be able to take out loans from a bank, based on the amountof harvested crops that the farmer owns but has not yet sold, but suchloans may be conditioned on the purchase of spoilage insurance. Theseller of aeration services, utilizing networked grain aeration havingcentralized control, may be able to provide this insurance because thecentralized control allows the seller of the service to adequatelymanage against grain spoilage. In particular, the use of networked grainaeration can reduce insurance premiums to an affordable level.

FIG. 3 is an exemplary block diagram of one embodiment of grain aerationsystem that can be installed in at a storage facility. As illustratedaeration controller 14 can be communicatively coupled to a centralcomputer. In any case, aeration controller 14 controls operation ofaeration fan 13, and possibly other grain management tools such asheaters, misters, or the like, based on sensed conditions.

Aeration controller 14 may also be coupled to a memory device 32, whichcan be used to store programmed aeration parameters, recent aerationdata prior to transmission to central computer 20, look-up tables, andpossibly computer readable instructions (software) that can be executedby aeration controller 14 to perform the aeration techniques describedherein. Memory 32 may also store programmable identification numbersassociated with aeration controller 14 and its various nodes. Anindication of storage capacity and current usage may also be stored.

If desired, aeration controller 14 may also be coupled to a userinterface (not shown) to provide on-site control and programmingcapabilities. The user interface may be used by on-site personal toaccess local aeration data, operational parameters, operational modes,and the like. The user interface may also be used to manually overridecentralized control, for example, to turn on the aeration fan. Suchmanual overrides, however, can be reported to central computer 20 sothat future aeration can account for and possibly adjust aerationbecause of the manual override. The user interface may take the form ofa browser application executing in a microprocessor, such as deployed ina laptop computer or a personal digital assistant (PDA) with wirelesscommunication capabilities. The user interface can be programmed toissue commands to controller 14.

As shown in FIG. 3, aeration controller 14 is coupled to one or morenodes, such as, for example, c-node 31, w-node 32, s-node 33, t-node 34,i-node 35, and f-node 36. The nodes correspond to various sensors,switches, or other units used by aeration controller 14 during aeration.Aeration controller 14 and respective nodes 31-36 may operate accordingto a master slave relationship in which aeration controller 14 pollsnodes 31-36 to obtain sensed information, and instructs nodes 31-36, forexample, when activation of aeration fan 13 should occur.

C-node 31 may correspond to an on/off relay switch used to turn aerationfan 13 on and off. Similar nodes may also be used for heaters, misters,or the like. C-node 31 may also have a static pressure gauge sensor. Inany case, c-node 31 can be used to switch aeration fan 13 on and off, atappropriate times identified by aeration controller 14. For example,aeration controller 14 may issue control signals to the c-node to causeaeration fan 13 to be switched on or off.

W-node 32 may be a weather node used to sense one or more ambientconditions surrounding the given storage facility. For example, w-node32 may include temperature sensor, a relative humidity sensor, abarometric pressure sensor, a rain gauge, a global positioning system(GPS) module, and possibly a wind speed/direction sensor.

F-node 36 may include a temperature sensor and a relative humiditysensor. F-node 36 may be used to provide feedback to aeration controller14 as outlined above. By way of example, one or more f-nodes may bepositioned after the aeration fan 13 but prior to the stored grain,e.g., in the plenum. Also, one or more f-nodes may be positioned in theexhaust of a crop storage facility 12, or in different strata of thegrain to provide a number of grain storage measurements.

T-node 34 may provide an interface to an external thermocouple module,which can be used to measure temperatures within a grain storage bin. Inother words, T-node 34 may correspond to a temperature sensor positionedto measure the current temperature of stored grain. T-node 34 may or maynot also include a relative humidity sensor.

S-node 33 may provide an interface to an external electronic scalemodule, used to weigh shipments of grain as they are brought in forstorage. Accordingly, s-node can be used by aeration controller 14 toidentify the amount of grain storage in the given storage facility. Asmentioned, memory 32 may store both an indication of storage capacityand current storage usage. Such information may be determined by s-node33. The amount of grain being aerated may affect pricing, in accordancewith one or more of the pricing schemes described herein.

I-node 35 may provide current metering capability by using a currenttransformer and rectifier circuit. Thus, i-node 35 can be used tomeasure electricity use, and to document information related toelectricity use. Such information may be stored locally by aerationcontroller and then transferred to central computer 20. Power suppliersmay desire collective estimations of electricity usage associated with anumber of facilities that use the aeration systems. In this manner,power usage of the fans controlled by the networked grain aerationsystem may merit special rates. If electricity supplied to a grainstorage site is subject to demand charges, the controllers may rotatefan usage so as to avoid these demand charges.

FIG. 4 is a flow diagram according to one embodiment of the invention.As shown, aeration controllers 14 are used to control aeration fansaccording to sensed conditions (41). Moreover, a central computer 20 canbe communicatively coupled to the aeration controllers 14 to monitoraeration (42). The custodian of the service can charge fees to customersbased on the amount of grain being aerated and the duration of thestorage (43). In this manner, customers may be more accepting of theaeration service because fixed costs associated with aeration hardwarecan be eliminated as a fixed expense to the customer.

FIG. 5 is another flow diagram according to one embodiment of theinvention. Again, aeration controllers 14 are used to control aerationfans according to sensed conditions (51), and a central computer 20 canbe communicatively coupled to the aeration controllers 14 to remotelymonitor aeration (52). The custodian of the service can sell grainspoilage insurance (53) because the centralized control allows for thecontrol needed to ensure against spoilage. In particular, centralizedcontrol of aeration can help keep premiums affordable, e.g., based onthe condition that the aeration service is used.

FIG. 6 is another flow diagram according to one embodiment of theinvention. Again, aeration controllers 14 are used to control aerationfans according to sensed conditions (61), and a central computer 20 canbe communicatively coupled to the aeration controllers 14 to remotelymonitor aeration (62). Central computer 20 can store aeration data (63),such as data pertaining to aeration fan operation, ambient conditions(or f-node conditions) during aeration, and various operationalparameters associated with the aeration controllers 14. Accordingly, ifan aeration controller 14 fails and is replaced (64), the aeration datacan be downloaded to the new aeration controller (65) to ensure thataeration will continue in a manner consistent with that prior to thefailure.

FIG. 7 is another flow diagram according to one embodiment of theinvention. Again, aeration controllers 14 are used to control aerationfans according to sensed conditions (71), and a central computer 20 canbe communicatively coupled to the aeration controllers 14 to remotelymonitor aeration (72). Predictable aeration results can be modeled forprospective customers to identify to the prospective customer, the valueof the system (73).

FIG. 8 is another flow diagram according to one embodiment of theinvention. Again, aeration controllers 14 are used to control aerationfans according to sensed conditions (81), and a central computer 20 canbe communicatively coupled to the aeration controllers 14 to remotelymonitor aeration (82). As grain is moved (83), a chain of custody canalso be recorded (84) to provide quality assurances to prospective grainpurchasers. Such assurances can result in premium prices for thedocumented grain.

FIG. 9 is a flow diagram illustrating an aeration technique that may beused as part of a networked grain aeration system or a more conventionalnon-networked grain aeration unit. As shown, aeration controller 14defines truncated temperature and/or relative humidity bands in order toimprove aeration for extreme climate scenarios (91). Aeration controller14 may also define an aeration budget (92), and accumulate a backlogwhen budgeted aeration time is not used. Eventually, when the ambientconditions fall within the truncated bands, aeration controller 14 canactivate aeration fan 13 in order to aerate the grain (94). Importantly,the truncation of the temperature and/or humidity bands can result inaeration that attains improved aeration results in terms of achieving atarget temperature and/or target moisture content.

FIG. 10 is another flow diagram according to one embodiment of theinvention. As shown aeration controller 14 defines climate bands such asa temperature band and a relative humidity band (101). For example, thebands may be programmed about target values, or may be defined about atarget determined as a function of current grain temperature. Therelative humidity band may be temperature dependent, and may further bedependent on the temperature of the stored grain relative to ambienttemperature.

Aeration controller 14 causes aeration fan 13 to aerate the grain whenthe local conditions fall inside the defined climate bands (102).Moreover, aeration controller 14 thereafter adaptively adjusts one ormore of the climate bands in a truncated manner (103). In other words,if aeration has primarily occurred for more than a defined amount oftime during wet conditions, e.g., conditions falling on the wetter sideof the relative humidity band, aeration controller 14 can truncate therelative humidity band to the dry side. Similarly, if aeration hasprimarily occurred for more than a defined amount of time during dryconditions, e.g., conditions falling on the dryer side of the relativehumidity band, aeration controller can truncate the relative humidityband to the wet side.

Then, when more aeration is desired (yes branch of 104), aerationcontroller 14 causes aeration fan 13 to aerate the grain when the localconditions fall inside the truncated climate bands (102). In thismanner, truncation of the climate bands, including the relative humidityband or the temperature band can be an adaptive feature of aerationcontroller 14 that improves the ability to achieve a target temperatureand/or moisture content for the stored grain. Adaptive truncation ofclimate bands during aeration may be enabled on aeration controller 14by selecting a specific operation mode that corresponds to thetruncation feature. Moreover, mode selection can be made offsite atcentral computer 20, if a networked grain aeration control system isemployed.

FIG. 11 is another flow diagram according to one embodiment of theinvention. As shown aeration controller 14 defines an aeration budget(111). For example, the budget may be a programmed value or inputprovided to aeration controller 14 that defines the maximum amount ofoperation time of aeration fan 13 per unit time, e.g., four hours perday.

Aeration controller 14 also defines climate bands such as a temperatureband and a relative humidity band (112). Again, the bands may beprogrammed about target values, or may be defined about a targetdetermined as a function of current grain temperature. The relativehumidity band may be temperature dependent, and may further be dependenton the temperature of the stored grain relative to ambient temperature.

One or more sensors 16 such as those described above measure theconditions surrounding the storage facility 12 (113). Aerationcontroller 14 polls the sensors 16 to obtain sensed data, and makes adetermination whether to aerate the grain based on the sensed conditions(114). In particular, to perform aeration (yes branch of 114), aerationcontroller 14 causes aeration fan 13 to aerate the grain, such as byinvoking a control node (c-node) to switch aeration fan 13 on.

If aeration does not occur (no branch of 114), then the unused portionof the aeration budget is backlogged (115). For example aeration may beregulated by aeration controller 14 such that aeration occurs only whenthere is remaining aeration budget unused in the backlog. In otherwords, if four hours per day are allocated, then four hours can be usedeach day. If some time is unused in a given day, that time is backloggedso that it can be used during subsequent days when the desiredconditions are present. Thus, if aeration does not occur on the firstday, but does occur on the second day, eight hours of aeration may occurin succession on the second day, i.e., four hours of budget for thesecond day plus four hours of backlog from the first day.

Furthermore, when more aeration is desired (no branch of 116), aerationcontroller 14 may redefine the bands, such as by adaptively truncatingthe bands as described above. Aeration may be stopped (yes branch of116) by manually overriding aeration controller 14. For example, oncethe grain is sold and removed from facility 12, the aeration controller14 may be powered down or otherwise disabled.

FIG. 12 is another flow diagram according to one embodiment of theinvention. As shown, aeration controller identifies an offset associatedwith operation of aeration fan 13 (121). For example, the offset may beidentified by a programmed theoretical offset value, or may be measuredby a feed back sensor 29. In either case, aeration controller 14accounts for the offset during grain aeration (122). In this manner,changes to the air introduced by aeration fan 13 from the sensed ambientconditions, such as a slight temperature increase, will not reduce theeffectiveness of aeration. Instead, the offset can be used by aerationcontroller 14 to adjust operation of the aeration fan 13 accordingly toaccount for heat production or other effects caused by the operation ofaeration fan 13.

Aeration is an important part of modern agricultural management. Inparticular, aeration can be effective in avoiding spoilage of grain,preserving grain weight, minimizing insect infestation, improvingmoisture content, re-hydrating grain, avoiding cracking of kernels,reducing stress cracks, and generally preserving and possibly improvingthe quality of stored grains. The techniques described herein canimprove grain aeration and the aeration service.

Many implementations and embodiments of the invention have beendescribed. For instance, may different features of a networked grainaeration system have been described. In addition other features andmethods have been described which may be used in a networked grainaeration system, or a more conventional non-networked aeration controlsystem. Nevertheless, it is understood that various modifications can bemade without departing from the spirit and scope of the invention. Forexample, the invention may use only some of the many features describedabove. Furthermore, other nodes are envisioned, including nodes thatmeasure barometric pressure or other ambient conditions. Moreover, sometechniques, such as truncating the relative humidity and/or temperaturebands based on climate may be implemented in non-networked systems.Accordingly, other implementations and embodiments are within the scopeof the following claims.

1-41. (canceled)
 42. A computer-implemented method for determining acontrol policy for a crop storage facility, the computer-implementedmethod comprising: obtaining a crop objective on a central computer;obtaining, on the central computer, at least one fan characteristic of afan associated with a crop storage facility that is in networkcommunication with the central computer; causing a processor of thecentral computer to determine a control policy configured to control atleast one controller of the fan to facilitate the crop objective on thecrop stored in the crop storage facility, wherein the determined controlpolicy is at least partially based on the obtained fan characteristic;and causing the processor of the central computer to send the controlpolicy to the at least one controller of the crop storage facility. 43.The computer-implemented method of claim 42, wherein the fancharacteristic is a fan size.
 44. The computer-implemented method ofclaim 42, wherein the fan characteristic includes an estimated heatvalue generated by the fan.
 45. The computer-implemented method of claim42, wherein the fan characteristic includes a measured heat valuegenerated by the fan.
 46. The computer-implemented method of claim 42,wherein the control policy is configured with a crop temperature valuethat accounts for the fan characteristic.
 47. The computer-implementedmethod of claim 42, wherein the control policy is configured with a croptemperature value band that accounts for the fan characteristic.
 48. Thecomputer-implemented method of claim 42, wherein the control policy isconfigured with an asymmetrical crop temperature value band thataccounts for the fan characteristic.
 49. The computer-implemented methodof claim 42, wherein the control policy is configured with a humidityvalue that accounts for the fan characteristic.
 50. Thecomputer-implemented method of claim 42, wherein the control policy isconfigured with a humidity value band that accounts for the fancharacteristic.
 51. The computer-implemented method of claim 42, whereinthe control policy is configured with an asymmetrical humidity valueband that accounts for the fan characteristic.
 52. A computer-readablestorage medium having computer-executable instructions for determining acontrol policy for a crop storage facility, the computer-executableinstructions comprising: obtaining a crop objective; obtaining at leastone fan characteristic of a fan associated with a crop storage facility;determining a control policy configured to control at least onecontroller of the fan to facilitate the crop objective on the cropstored in the crop storage facility, wherein the determined controlpolicy is at least partially based on the obtained fan characteristic;and sending the control policy to the at least one controller of thecrop storage facility.
 53. The computer-readable storage medium of claim52, wherein the fan characteristic is a fan size.
 54. Thecomputer-readable storage medium of claim 52, wherein the fancharacteristic includes an estimated heat value generated by the fan.55. The computer-readable storage medium of claim 52, wherein the fancharacteristic includes a measured heat value generated by the fan. 56.The computer-implemented method of claim 52, wherein the control policyis configured with at least one member of a group comprising: a croptemperature value that accounts for the fan characteristic, a croptemperature value band that accounts for the fan characteristic, anasymmetrical crop temperature value band that accounts for the fancharacteristic, a humidity value that accounts for the fancharacteristic, a humidity value band that accounts for the fancharacteristic, and an asymmetrical humidity value band that accountsfor the fan characteristic.
 57. A system for determining a controlpolicy for a crop storage facility, the system comprising: at least oneprocessor; and at least one memory having computer-executableinstructions stored thereon, wherein the computer executableinstructions are configured for: obtaining a crop objective; obtainingat least one fan characteristic of a fan associated with a crop storagefacility; determining a control policy configured to control at leastone controller of the fan to facilitate the crop objective on the cropstored in the crop storage facility, wherein the determined controlpolicy is at least partially based on the obtained fan characteristic;and sending the control policy to the at least one controller of thecrop storage facility.
 58. The system of claim 57, wherein the fancharacteristic is a fan size.
 59. The system of claim 57, wherein thefan characteristic includes an estimated heat value generated by thefan.
 60. The system of claim 57, wherein the fan characteristic includesa measured heat value generated by the fan.
 61. The system of claim 57,wherein the control policy is configured with at least one member of agroup comprising: a crop temperature value that accounts for the fancharacteristic, a crop temperature value band that accounts for the fancharacteristic, an asymmetrical crop temperature value band thataccounts for the fan characteristic, a humidity value that accounts forthe fan characteristic, a humidity value band that accounts for the fancharacteristic, and an asymmetrical humidity value band that accountsfor the fan characteristic.